Gas burner assembly



MalCh 23, 1965 A T, WALSTAD GAS BURNER ASSEMBLY 2 Sheets-Sheet 2 Original Filed June 6, 1958 Aff/omey United States Patent O 13 Claims. (Cl. 158-109) This application which relates toa burner assembly is a continuation of my co-pend-ing application Serial No. 740,465, led June 6, 1958, now abandoned. The applicationV relates more particularly to a burner assembly for use in the intermediate and: late heating .stages ofl billet heating furnaces. consisting of a series of barrel type chambers such as shown in Hess Patent No. 2,638,333, dated May 12, 1953. The burners previously used for this purpose are generally of the type shown in Furczyk Patent` No. 2,561,793, dated July 24, 1951. The burner tip shown in this patent` is subjected tofast cooling and heating. and the temperature strains resulting from this change in tiring. rate distort and crack the. burner tips or the supports for the burner tips. This in turnimpairs the burners efiiciency and the billet heating ability, thereby requiring excessivel repair and maintenance.

It is. therefore an object ofV my invention to provide a nozzle mixA radiant type burner which greatly reduces the temperature strains. in the burner tip due to changes in tiring rates.

Another object is to provide such a burner having irnproved life and sustainedV eiiiciency over a longer period of. time than burners previously used, resulting in reduced maintenance cost.

Still another object is to provide a nozzle mixl burner of simple design and low initial and replacement cost.

These and other objects will be more apparent after referring to the following specification and attached draw'- ings, in which:

FIGURE l is a cross section of a barrelv type billet heating furnace with the burner assembly incorporating therein; Y

FIGURE 2 is a sectionai view showing the detailszof the burner assembly;

FIGURE 3 is an enlarged View showing the burner tip;

FIGURE 4 is a view looking to the left of FIGURE 3;

FIGURE 5 is a sectionaf view taken on; the line V-V of FIGURE 4; and

FIGURE. 6 is a fragmentary sectional View of a burner assembly showing a modification of the burner tip and forward end ofthe burner assembly.

Referring'rnore particularly to the dra-wings, reference numeral 2 indicates the heating chamber of the furnace. An opening 4 is provided at each end of the furnace chamber 2 through which billets B enter and leave the chamber 2. Chamber 2 is surrounded by arefractory wall 6 having a clean out hole 8 through the bottom thereof and a venting hole 10 through the top thereof. A metal shell 12' surrounds the refractory 6. Insulation 14 may be provided between the metal shell 12 and the refractory 6 where desired'. Four burner tunnels 16 extend through the refractory lining 6 and metal shell 12. Cup shaped openings 18 are provided in the inner *surface of the refractory lining 6. A tunnel 16 intersects the bottom of each of the cup shaped openings 18. The cup shaped openings 18 are preferably substantially hemispheres. The burner assembly includes a burner body 20 which may be fastened to the metal shell 12 in any suitable manner such as by means of bolts 22. A straight air tube 24 projects into the opening 16 and is fastened to the burner body 20: inv any suitable manner. As shown; the air tube 24 is madeV up of a main tube 26,

y, 3,174,531 Patented, Mar. V21?, 1965 a forward extension 28 and a mounting ring 30 all welded together. An L-shaped clamp 32 receives the mounting ring 30 and is fastened to the body 20 by means of cap screws 34, thus fastening the air tube 24 to the burner body 20. Openings 36and 38 are provided in the burner body 20 in axial alignment with the air tube 26. Opening 40 is provided in the body 20 through which air is delivered into the. air tube. 24. A straight imperforate raw fuel gas tube 42 passes through a standard packing gland 44 mounted inthe opening 36.. A ring-46 is fastened to the tube 42 on the outside of packing glandY 44V by means of a set screw 48. A burner tip 50 is threaded on the forward end of gasl tube 42'. Burner tipv 50 is of general T-shape with its headl projecting into the cup shaped opening i3. The head end52 is closed, a plurality of openings 54 extending therethrough withY their axes diverging outwardly from the axisof the burner tip. The axes of the openings 54 are arranged at anangle S6 of 10 to a transverse plane through the burner tip. Inner face 58 of the headend4V 52 is preferably arranged at an angle 60 of 20 with a` transverse plane through the burner tip. Three lugsior fins 62 are provided on the inner surface 58. The inner face of each lug 62 is arranged at an angle 64 of 15 with a transverse plane through the burner tip. The forward end of the extension 28 is also arranged` at an angle 64 so thatthe inner face of lugsf 62 abut thereagainst. Tip` 50A has an axial opening 66 therein which is threaded at 63 for receiving the gas tube 42. An annular ring '70 is provided'on the burner tip Sli?` as shown. Since theA air tube 24 is sepa.-

rate'from the gas tube 42 and burner tip 5.0 thegas tube and burner tip can expand axially at the end adjacent the burner tip, with respect to thel air tube on thermal changes.

In assembly, the burner tip 50 is held in centered position by means of the lugs 62 and the inner face` of the lugs 62 in combination with the ring 4'6 holds the burner tip 50 in locked position. Air, oxygen or a mixture thereof enters the burner body 20 throughopening 40, passes between the air tube 24 and gas tube 42, and out through a slot 72 provided. between the end of' the air tube extension` 28 Aand the inner face 5S of the burner tipl 50. It will. be seen that the inner face of the head end of the burner tips slopes radially outwardly toward the forward end of the tip at a lesser angle tothe axis of the gas tube than the axes of the openings 54. This provides for better mixing of the gas and? air'. The ring 70 acts to meter the How of air through slot 72.

FIG-URE 6 shows` a slight modification of my invention in which burner tip 50 has a metering ring 70'v welded thereto and in which the centering lugs 62 are omitted. To center the burner tip 50' and lock it in position air tube extension 28 is provided with threaded radialV holes 74 for receiving set screws '76. The set screws 76 pass through the openings 74 and bear against the burner tipV 0".

While two embodiments of my invention have. been :shown and described, it will be apparent that other adaptationsY and modifications may be made without departing from the scope, of the following claims.

I claim:

1. A nozzle mix radiant burner assembly comprising a burner body, a straight air tube fastenedy to said burner body, a` straightr imperforate gas raw fuel tube extending through said body into said air tube, and a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and With its head end projecting radially beyond the opening of said air tube, the` head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

2. A nozzle mix radiant burner assembly comprising a burner body, a straight air tube fastened to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, and means extending between said burner tip and said air tube to position said burner tip in centered position within said air tube, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

3. A nozzle mix radiant burner assembly comprising a burner body, a straight air tube fastened to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, and an air metering ring between said burner tip -and the inside of said air tube, said air tube being separate from the gas tube and burner tip at the end edjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

4. A nozzle mix radiant burner assembly comprising a burner body, a straight air tube fastened to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, means extending between said burner tip and said air tube to position said burner tip in centered position within said air tube, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, and an air metering ring between said burner tip and the inside of said air tube, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube Aon thermal changes.

5. A nozzle mix radiant burner assembly comprising a burner body, a straight air tube fastened to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of enlongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, and means extending between said burner tip and said air tube to position said burner tip in centered position within said air tube, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, the axes of said openings in said burner tip being at a greater angle to the axis of said gas tube than the inner face of the Ihead end of said burner tip, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

6. A nozzle mix radiant burner assembly comprising a refractory wall having a cup shaped opening in its inner surface and a generally cylindrical opening therethrough intersecting the bottom of said cup shaped opening, a straight air tube extending through said cylindrical opening, a burner body mounted adjacent the outer end of said cylindrical opening, means for fastening said air tube to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, and a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting into said cup shaped opening and radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas Openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

7. A nozzle mix radiant burner assembly comprising a refractory wall having a cup shaped opening in its inner surface and a generally cylindrical opening therethrough intersecting the bottom of said cup shaped opening, a straight air tube extending through said cylindrical opening, a burner body mounted adajcent the outer end of said cylindrical opening, means for fastening said air tube to said burner body, a straight imperforate gas raw fuel tube extending through said body into said air tube, and a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting into said cup shaped opening and radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner'tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, means extendingv between said burner tip and said air tube :to position said burner tip in centered position within said air tube, the inner face of the head end of sa'i'd burner tip sloping radially outwardly toward' the forward end of' said tip and being spaced from the forward end of said air tube to dene an air slot therebetween, -sa'id air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that saidv gas tube andburner tip are free to expand axially with respectto said air tube on thermal changes.

8. A nozzle mix radiant burner assembly comprising a refractory Wall' having a cup shaped opening in its inner surface and a generally cylindrical opening therethrough intersecting the bottom of said cup shaped opening, a straight air tube extending through said cylindrical opening, a burner body mounted adjacent the outer end of said cylindrical opening, means for fastening said air tube to said burner body, a straight irnperforate gas raw fuel tube extending through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting into said'cup shaped opening and radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced -apart a distance substantially greater than the transverse section thereof, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to dene an air slot therebetween, and an air metering ring between said burner tip land the inside of said air tube, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially Withrespect to said air tube on thermal changes.

9. A nozzle mix radiant burner assembly comprising a refractory wall having a cup shaped opening in its inner surface and a generally cylindrical opening therethrough intersecting the bottom of said cup shaped opening, a straight air tube extending through said cylindrical opening, a burner body mounted adjacent the outer end of said cylindrical opening, means for fastening said air tube to said burner body, a straight imperforate gas raw fuel tube extending'through said body into said air tube, a one piece generally T-shaped burner tip mounted on the inner end of said gas tube in axial alignment therewith and with its head end projecting into said cup shaped open-ing and radially beyond the opening of said air tube, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantial-1y greater than the transverse section thereof, means extending between said burner tip and said air tube to position said burner tip in centered position within said air tube, the inner face of the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, and an air metering ring between said burner tip and the inside of said air tube, said air tube being separate from the gas tube and burner tip at the end adjacent the burner tip so that said gas tube and burner tip are free to expand axially with respect to said air tube on thermal changes.

l0. A nozzle mix radiant burner assembly comprising a burner body, said body having an axial opening therethrough, a straight air tube in axial alignment with said axial opening, means det-achably fasteningV said air tube to said burner body around the exit end. of said axial opening, a straight imperforate raw gas' fuel tube extending through said axial opening` into said` air tube coaxially therewith, a packing` gland mounted in the entry end of said axial opening for slidablysupporting said fuel gas tube, means for introducing air' into said body around said fuel gas tube, a unitary generally T- shaped in section burner tip, means mounting said burner tip on the exit end of said fuel' gas tube," said T-shaped burnerV tip having an axial openingextending from the entry end toward the head endt thereof, the head end of said burner tip having a diameter greater than the inner diameter of said air tube, the inner,` face of the head end of said burner tip: 'slopingA radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to deineran air slot therebetween, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging out- K wardly from the axis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, the axes of said openings in said burner tip being at a greater angle to the axis of said gas tube than the inner face of the head end of said burner tip, and longitudinal centering lugs on said burner tip extending to the tinner wall of said air tube to position v said burner tip in centered position within said air tube.

11. A nozzle mix radiant burner assembly according to claim 10 including a refractory wall having a cup shaped opening in its inner surface and a generally cylindrical `opening therethrough intersecting the bottom of said cup shaped opening, said Iair tube extending through said cylindrical opening and said burner body being mounted adjacent the outer end of said cylindrical opening, the head end of said burner tip projecting into said cup shaped opening.

12. A nozzle mix burner assembly comprising a burner body, said body having an axial opening therethrough, a straight air tube in axial alignment with said axial opening, the exit end of the wall of said air tube being beveled and extending outwardly at an angle from its inlet end, means detachably fastening said air 4tube to said burner body around the exit end of said axial opening, said last named means including a mounting ring attached to the entry end of said air tube, said mounting ring having an outside diameter greater than the outside diameter of said air tube, an L-shaped clarnp surrounding said mounting ring with one -leg thereof extending toward said air tube and abutting said mounting ring and means attaching said L-shaped clamp to said body, la straight imperforate raw gas fuel tube extending through said axial opening into said air tube coaxially therewith, a packing gland mounted in the entry end of said axial opening for slidably supporting said fuel gas tube, means for introducing air into said body around said fuel gas tube, male threads on the exit end of isaid fuel gas tube, a unitary generally T-shaped in section burner tip threaded on said male threads in axial alignment with said fuel gas tube, said T-shaped burner tip having an axial opening extending from the entry end toward the head end thereof, the head end of said burner tip having a diameter greater than the inner diameter of said air tube, the inner face 0f the head end of said burner tip sloping radially outwardly toward the forward end of said tip and being spaced from the forward end of said air tube to define an air slot therebetween, the head end of said burner tip being closed with a plurality of elongated and enclosed gas openings therethrough having their axes diverging outwardly from the Vaxis of said burner tip toward the discharge end of the burner, said gas openings being spaced apart a distance substantially greater than the transverse section thereof, the axes of said openings in said burner tip being at a greater angle to the axis of said gas tube than the inner face of the head end of said burner tip, longitudinal centering lugs on said burner tip arranged to position said burner tip in centered position within said air tube, said centering lugs having a portion thereof arranged at a bevel and bearing against the exit end of said air tube, and a circumferential metering ring surrounding said burner tip on the inlet side of said lugs.

13. A nozzle mix radiant burner assembly according to claim 12 including a refractory Wall having a cup shaped opening in its inner surface and a generally cylindrical opening therethrough Vintersecting the bottom of said cup shaped opening, said air tube extending through said cylindrical opening and said burner body being mounted adjacent the outer end of said cylindrical -opening, the head end of said burner tip projecting into said cup shaped opening.

References Cited in the le of this patent UNITED STATES PATENTS France Nov. 21, 1949 

1. A NOZZLE MIX RADIANT BURNER ASSEMBLY COMPRISING A BURNER BODY, A STRAIGHT AIR TUBE FASTENED TO SAID BURNER BODY, A STRAIGHT IMPERFORATE GAS RAW FUEL TUBE EXTENDING THROUGH SAID BODY INTO SAID AIR TUBE, AND A ONE PIECE GENERALLY T-SHAPED BURNER TIP MOUNTED ON THE INNER END OF SAID GAS TUBE IN AXIAL ALIGNMENT THEREWITH AND WITH ITS HEAD END PROJECTING RADIALLY BEYOND THE OPENING OF SAID AIR TUBE, THE HEAD END OF SAID BURNER TIP BEING CLOSED WITH A PLURALITY OF ELONGATED AND ENCLOSED GAS OPENINGS THERETHROUGH HAVING THEIR AXES DIVERGING OUTWARDLY FROM THE AXIS OF SAID BURNER TIP TOWARD TO THE DISCHARGE END TO OF THE BURNER, SAID GAS OPENINGS BEING SPACED APART A DISTANCE SUBSTANTIALLY GREATER THAN THE TRANSVESE SECTION THEREOF, THE INNER FACE OF THE HEAD END OF SAID BURNER TIP SLOPING RADIALLY OUTWARDLY TOWARD THE FORWARD END OF SAID TIP AND BEING SPACED FROM THE FORWARD END OF SAID AIR TUBE TO DEFINE AN AIR SLOT THEREBETWEEN, SAID AIR TUBE BEING SEPARATE FROM THE GAS TUBE AND BURNER TIP AT THE END ADJACENT THE BURNER TIP SO THAT SAID GAS TUBE AND BURNER TIP ARE FREE TO EXPAND AXIALLY WITH RESPECT TO SAID AIR TUBE ON THERMAL CHANGES. 